1. Technical Field
The present invention relates to a communication system in which a power feeding device and a power receiving device are connected with each other through a cable, and communication of control signals necessary for charge control based on power feeding from the power feeding device to the power receiving device is performed through the cable.
2. Description of Related Art
In recent years, electric and hybrid vehicles have become widespread, which are provided with devices such as a motor, a battery and the like, and which run by the motor driven by power stored in the battery. An electric vehicle needs to be charged from an external power feeding device to a battery. A hybrid vehicle includes a plug-in hybrid vehicle which can also be charged from an external power feeding device to a battery. In a vehicle charged from the outside to its battery, a plug of a charge cable connected to an external power feeding device is connected to a connector device at a feeding port provided at the vehicle and power is fed through a charge cable from the power feeding device to the battery of the vehicle so as to charge the battery.
Moreover, in charging from a feeding device to a vehicle, a charge control system may be employed in which a control cable transmitting and receiving a control pilot signal to/from the power feeding device and the vehicle, and charge control is performed based on the control pilot signal (see Japanese Patent Application Laid-Open No. 2009-106053, for example).
Furthermore, as power feeding from a power feeding device has widely been commercialized, it has been required to employ communication function of transmitting and receiving information for management of charge amount management, accounting management and the like between a vehicle and a power feeding device.
A communication system has thus been noted in which communication signals including information used for management and the like are superimposed onto control pilot signals communicated through a control cable. In this communication system, such a configuration is employed that an electromagnetic inductive signal transformer (a circuit element such as a coupling transformer) which superimposes or separates signals onto or from a control cable is connected to a branch line from each control cable.